Unfortuantely my GP said it was 'just side effects of the med and will settle down if I keep taking it' - after that they lost interest - no official diagnosis of serotonin syndrome or akasthesia. They then gave me a dx of agoraphobia and severe anxiety disorder - but I didn't have these things before that one dose of Celexa.
I've had bad psych med reactions over the decades, but not to the SSRI class of drugs (Celexa, Prozac, Paxil, Zoloft... off the top of my head). Well, Paxil did give me bad insomnia for a couple weeks.
But the SSRI's really didn't help much either.
When ME/CFS was in remission, doctors would say "look the drug is working". And when I relapsed on the same drug, psychiatrists would call it "poop out" and say the drug just stop being effective.
That way they couldn't be wrong.
For example, I took Zoloft 200mg/day for more than 3 years (1991-1994) during a remission and stopped it to try another drug during a relapse because it wasn't helping ("poop out").
In retrospect, I don't think SSRIs did anything positive or negative for my varied neuro symptoms, PEM, fatigue, or anxiety. It's all better explained by my normal 2-4 years relapse/remit ME/CFS disease cycle.
SSRIs did slightly help my secondary depression during relapse. But getting correctly diagnosed with ME/CFS and learning how to pace has helped my secondary depression more than any SSRI ever did.